Dopplerov efekt u ubrzanom sustavu i određivanje ubrzanja izvora zvuka

master's thesis

• Title (english): The Doppler effect in an accelerated system and determining the acceleration of a sound source
• Author: Fabijan Prević
• Mentor: Nikola Poljak (mentor)
• Committee member: Nikola Poljak (predsjednik povjerenstva)
• Committee member: Damir Pajić (član povjerenstva)
• Committee member: Ana Sušac (član povjerenstva)
• Committee member: Mario Novak (član povjerenstva)
• Committee member: Gorjana Jerbić-Zorc (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2016-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Tijekom studija i u srednjoj školi Dopplerov efekt se obraduje i matematički opisuje za specifičan slučaj kad se izvor zvuka i opažač gibaju konstantnim relativnim brzinama. U ovom diplomskom radu će se pokušati opisati slučaj kad ta brzina nije konstantna, već se mijenja u vremenu. Konkretnije; razmotrit će se slučaj kad izvor zvuka jednoliko ubrzava, a opažač miruje. U skladu s tim pokušat će se teorijski predvidjeti kako se frekvencija koju registrira opažač mijenja za vrijeme ubrzavanja izvora zvuka, a zatim isto i eksperimentalno provjeriti te usporediti teorijsko predviđanje s dobivenim eksperimentalnim podacima. Pri eksperimentalnoj realizaciji je za uzrok jednoliko ubrzanog gibanja odabrana isključivo jedna sila, naime, gravitacijska sila. Budući da neke sile poput otpora zraka i sl. nisu mogle biti eksperimentalno eliminirane, akceleracija izvora zvuka nije mogla biti jednaka akceleraciji slobodnog pada, odnosno 9,81 m/s2, već je neizbježno morala biti nešto manja. Iz tog razloga se uz analizu zvuka provodila i analiza videozapisa akcelerirajućeg izvora zvuka, a iz koje je potom određena najvjerojatnija stvarna akceleracija izvora zvuka. Konačno, u ovom će se radu usporediti dobivene akceleracije izvora zvuka kao rezultati analiza videozapisa te zvučnog zapisa s pretpostavkom veće točnosti rezultata dobivenog analizom videozapisa te ocijeniti kakvoća analize Dopplerovog efekta za određivanje akceleracije jednoliko ubrzanog tijela.

Abstract (english)

In secondary school and college physics courses the Doppler effect is studied and calculated in a specific case in which a sound source and observer are moving at a constant relative velocity. This thesis will try to describe the case in which the velocity is not constant but changes with time. More precisely, it will analyze the case of a uniformly accelerated sound source and a stationary observer. In accordance with that, the thesis will try to theoretically predict the changes in frequency measured by the observer during the acceleration of the sound source. This prediction will then be experimentally verified and the obtained data will be compared to the theoretical prediction. There is only one cause of uniformly accelerated motion of the sound source in our experimental setup: gravity. Considering the fact that air resistance and other disturbances could not be experimentally eliminated, inevitably the sound source acceleration had to be below the free fall acceleration of 9; 81 m/s2. For that reason, the video material with the falling sound source was examined alongside sound analysis to determine the most likely actual acceleration. Finally, this paper will compare the sound source accelerations obtained by both sound and video analyses, which accounts for greater accuracy of results, and evaluate the quality of the Doppler effect analysis for determining the acceleration of a uniformly accelerated body.

• Keywords: Dopplerov efekt
• Keywords (english): Doppler effect
• Language: croatian
• URN:NBN: urn:nbn:hr:217:035598
• Study programme: Title: Physics and Computer Science; specializations in: Education; Course: Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike i informatike (magistar/magistra fizike i informatike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-03-05 11:04:44